Many engineers have come across Digilent Pmods standard and even included Pmods in their systems. Pmod modules allow for more effective designs by routing analog signals and power supplies only where they are needed, and away from digital controller boards. However, Pmods aren't for high speed communication. So, engineers can't use Pmods in high speed instrumentation systems or digital signal processing applications. At the same time, high speed FPGA Mezzanine Cards are bulky and comparatively pricey. To solve this problem, Digilent makes use of SYZYGY standard and launch a new line of expansion modules for high-speed control, signal processing, or test and measurement applications


SYZYGY Open Source Standard


Similar to Pmod standard, SYZYGY is an open standard from Portland, Oregon’s Opal Kelly. It fits – in cost, size, and performance – somewhere between the Pmod and FMC standards. Although not much larger than many Pmods, SYZYGY-compatible modules are capable of high-bandwidth connections to an FPGA, enabling very compact and cost-effective high performance I/O. The small, SYZYGY standard form factor recommends them for compact, configurable, rugged systems.


Comparison between Pmod, Syzygy and FMC standard. Source:


Digilent Zmods


Digilent starts the Zmods line with two data acquisition Zmods - Zmod ADCZmod ADC and Zmod DACZmod DAC. The SYZYGY compatible connectors provide enough data transfer bandwidth (BW) for dual-channel, 100MSPS. The high BW and sampling rate, the flexible input/output range, the high resolution and the flexibility provided by the FPGA interface make them ideal for a wide variety of applications.




zmod adc

Zmod ADC 1410


zmod dac

Zmod DAC 1411


A pair of Zmod DAC / Zmod ADC, together with a SYZYGY compatible FPGA carrier, like Eclypse Z7Eclypse Z7, could be used for closed analog loops with digital control, digital filters with analog input and output, hardware-in-the-loop, digital signal processing, high frequency modulators/demodulators, real-time image processing, SDR, etc.


Eclypse Z7 + Zmod ADC + Zmod DAC

Zmods Support Materials


The following tutorials step through the process of creating a hardware platform that supports Zmods.


Digilent provides a set of libraries supporting Zmod modules on both Linux and baremetal (standalone) platforms. The Zmod Base Library implements functionality common to all Zmods. For each Zmod, separate libraries are implemented, based on Zmod Base Library.